where \(T^{comp}_{j}(e_1, e_{2})\)  is the time taken by UAV \(j\)  to compute \(e_1* e_{2}\) . \(\alpha _{j} > 0\)  and \(\mu _{j} > 0\)  are shift and straggling parameters, respectively, which characterize the computing power of UAV \(j\) .
\(c(n_1, n_2)\)  represents the computation load required for computing \(e_1* e_{2}\) .
To derive this value, we assume that the Fast Fourier Transform (FFT) is used by each UAV to calculate the convolution of two vectors with arbitrary lengths. Hence, we have [1]}, [2]}:
\(c(n_1, n_2)& = \mathcal {O} \big ((n_{1} + n_{2} - 1)(\log (n_{1} + n_{2} - 1) + 1)\big ) \nonumber \\& = C(n_{1} + n_{2}) \log (n_{1} + n_{2}) \nonumber \) 
